Flush type toggle latch



Aug 23, 194. A. |A @ANDER 2,479,921

FLUSH TYPE TOGGLE LATCH Filed March l5, 1945 2 Sheets-Sheet' l Au@ 23,99. AF. @ANDER 2,479,9m

FLUSH TYPE TOGGLE LATCH Filed March 15, 1945 2 sheets-sheet 2 till M)Patented Aug. 23, 1949 UNITED STATES PATENT OFFICE FLUSH TYPE TOGGLELATCH Arnold F. Gander, Berkeley, Calif.

Application March 15, 1945, Serial No. 582,866

2 Claims. 1

This invention relates to latch mechanisms and particularly to those ofa type adapted to quick release and to uses such, for example, as thelatching of doorscovering inspection openings in aircraft, automobilesand the like.

A general object of the invention is to provide an improved and ruggedlatching mechanism which, although light in` weight and made of arelatively few parts is also dependable in operation and to hold rmlywhen latched in spite of vibration and jolts.

The present invention has for another object the provision of a latchmechanism having only the operating element thereof exposed to the outersurface of the part upon which it is mounted and being flush therewith.i y

Another object of this invention is to provide a latch mechanism havingan exposed operating element so constructed and arranged that it forms aseal against the weather and elements when closed and is notrenderedinoperative by bad weather conditions.

It is a further object of the invention to provide an improved latchmechanism adapted to use in connection with the closure for inspectionopenings of aircraft and the like, and which is compact and may bemanufactured at low cost without sacrificing dependability of operationand long life.

In one of its more specic aspects, my invention has for an object thelprovision of a latch mechanism including an actuating element upon whichforces normally encountered in use, such as air pressure, tend toneutralize or balance on two sides of the element.Y Other objects andadvantages of the invention will be apparent from the followingdescription and the accompanying drawings, in which similar charactersof reference indicate similar parts throughout the several views.

Referring to the drawings of which there are two sheets:

Fig. 1 is a fragmentary side elevational view of one side of a wallsection of an airplane or the like, showing one type of door to which apreferred embodiment of my latch mechanism is attached;

Fig. 2 is an enlarged fragmentary view looking at the opposite side ofthe door from that shown in Fig. 1 which depicts a preferred form of mylatch mechanism in rear elevation;

Figs. 3 and 4 are sectional views of the door and latch mechanismAindicated in Figs. 1 and 2 wherein the section for both views is takenalong the line 3-3 of Fig. 2 and Fig. 3 shows the latch mechanism in aholding position and Fig. 4 shows the latch mechanism in a retractedposition;

Figs. 5 and 6 are respectively sectional views taken substantially onlines 5-5 and 6--6 of Fig. 2;

Fig. '1 is a View similar to Fig. 1 which shows the adaptation of amodified form of my invention to the door structure of an airplane orthe like;

Fig. 8 is a View of the modied. form of my invention shown in Fig. 7drawn to a larger scale and disclosing the side opposite from that showninFig.'l;

Figs. 9 and 10 are sectional views, with the sections for both beingtaken substantially along the line 3--9 of Fig. 8, and wherein Fig. 9shows the latch mechanism in a holding position and Fig. 10 depicts thelatch mechanism in a retracted position; and

Figs. 11, 12 and 13 are respectively sectional views taken substantiallyon lines II-I l, I2-I2 and l3-I3 of Fig. 9 and viewed in the directionindicated by the arrows.

Referring to the illustrative embodiment of my invention which is shownin Figs. 1 to 6 inclusive, my preferred form of latch mechanism 20 isindicated in its adaptation to the releasable holding of a door 22,which door is swingably supported with respect to a wall 23 by a hinge24 so as to provide a closure for an opening 25 in the wall. The wallindicated comprises an outer covering or skin 26 which has secured tothe inner surface thereof a door jamb 2l against which the edges of thedoor seat to provide a substantially tight closure for the opening;Preferably near the edge of the door opposite that which is hingedlysupported, an aperture 28 is provided for access to the latch mechanism2U and manual operation thereof from the outside of the door.

In its preferred form, the latch mechanism 20 includes a base v23 havingmounting flanges 30 and integral supporting flanges 32. One surface ofthe base 29 opposite the side from which the supporting anges 32 projectis at or adapted to conform closely to the inner surface of the door 22.An aperture 33 in the base 29 is somewhat larger than the aperture 28 inthe door and is concentrically disposed with respect to the aperture 28to provide a sealing surface 34 around the aperture 28 when the base issecured to the inner surface of the door by suitable fastening meanssuch as rivets 35.

Desirably the supporting ilanges 32 have parallel end portions 36 and 31at their opposite ends, While the intermediate portions are curvedoutwardly around the aperture 33. Rotatably mounted between thesupporting flanges 32 by pin 38 is a latch actuator 39. The pin 38extends through the parallel end portions 31 and a bearing portion 49 atone end of the actuator 39 and is secured in place by suitable meanssuch as a cross pin 42. The.. actuatorL 39, has integral flanges 4'3extendin'g across thea. inner suraca thereof from the bearing portion 40in spaced and' parallel relation. In alignment with the apen ture 28 theactuator 39 has a protruding mid'- portion 44 adapted to lt intothe?apertura28El and an integral projecting ilange Ilsurrounding, theprotruding portion which conforms to and'A seats against the sealingsurface;3.4;5tcr:provide;Av

a sealed closure for the aperture 28 when the latch mechanism is in. theholding position as shown in Fig. 3. In order to preserve a smooth andstreamlined outer-surface;- the protruding mid-portion of@ the actnatorfis= lishf" with4V the outer surface of the door when the flange 45iisseated-1 against/: the' sealingT surface 342 Thus'- the side of the doorand provides a substantially weathereproofseal fbrfftheY access aperture28 when thel doorv isr closed? and lielil by the latcli mechanism. Y K

The actuator 39 is biased to the closed position by atorsifon spring:46,1"whioh'spring, byfpref'erence;Y has sidel'oopsf 4T encircling theends: offtli'e bearing portionftll' anv intermediate connecting portion48 which connects the loops and@ eng-ages the sidesvof-*thee angesrl13fand engagel the rear surface offh `the actuator-- 39;

Adi acenthe-swingihg `endi1tlie actuator 3 95, latchboltl 52W-issupportedl forfrotaryfswinging movement relative to the base bysfapin=-52wiiicli extend'sltliroughitlef-parallel end portions'` 3610ithe--ilanges- 32 and? alf-bearing portion- 532 ofi the latci'rY bolt;The@ pixrf- 55 is securedfin i place by fastening means suchasffacrosspiir 54%' The latchcbcltl'ti has an: integral flatchingportion- 55 andL is-` swirrgalilet abouti-1 the anis#V or?" theL1 pin 'i52 alf-holding 1 position linftlex l'aticlfingA portion:Y engages: awkeeperv 5fsecureclil to` thee door jambi'fbyffastening meanssucht:antrivetsiVY The holdingA positionao'theflat'chebolt Billieilliist'rated im Eig.' 3i., Whenr swungfto. afv retracted position?,`sucht asv that: illustrated ini-Fig: Y the'wl'atci bol-'t 59disengageathevkeeper wandallowsltlie' toiswin'gfopen--l Actuat-i'omofthe latch bolt 50 byimanua-l movesment. ofthe l actuaton39Vis.Yaffectedthroug-l-a con-knection :betweeristheiflatchi b'cfltA and?.theT swinging endi of thea actuator: whichiisprovide'dby aliiik' 59'.Ationeaend theelinkrEais notatabltvconnected toithellatch bolt atvaipositionxfdisplaced From vthe axis of the latch bolt supporting pinBETfbyfa/'piri 'Iheeother enidsotf'thealnkrisrnotatabl connected,`to?thasuzvingingftendifv oftthe.- actuatorA byfa 611i:x whichr: extends;thrcughi the'.l actuator flanges: 43.. In the retractedpositione of."tha latchsbcilt;` which is 1illustrated in: Fig; 4;. aninte1 gral stop:-62; on onesidez ot theouterrsurface ci? therbeaningportio1r-53toftheflatclr bolt engages aaco-actingstop 63,'on2the endsurfacezofftheflink 59' torpreventimovenrentof thezlatchvbolt beyond a,positionfim winch; ther axes of the z pins; 595i and arel in:substzmtial-` alignment with; the-f axis oi,th efpin' 52. Y

By the disclosedconstruct'ron:andsarrangement 0E: pants', .the actuatcrv39;? scn'ves:l aa. a; paint@ off, a

toggle connection by which the latch bolt 50 is rmly urged to itsholding position so as not to be affected by vibration or jarring, whilethe latch bolt itself serves as a part of another toggle connectionwhich holds the latch bolt in a, retracted position against the biasingforce of the spring 46 when operated thereto by manual movement of theactuator 39.

The. iunction of the, toggle.. connection for holding;` the:` latch`Vbolt v5w rmly engagement with the keeper 56 may be understood byreference to Fig. 3. As there illustrated, when the latch bolt 50 is inthe holding position the axes oii'ftlie pins-.591 and 60 which providethe connections of the link 58 to the latch bolt and actuator,

respectively, approach alignment with the axis of; thaL pimBaf. uponwhich the actuator is rotatably, supported. If it is desired that thelatch bolt'sliallbe securely held in the holding position when theactuator is in the holding or closed positi-ongthiefparts-emay#besdconstructedthatthe axisK of-. the pirr 60 is'actuallyi'alignedwith the axesfoitliepii'xs59ffafnd38ior-crossestvtheiflnebatween the axesnofr'tlewpins 59land 313ithis instance?" however; tha dbor'f cannct bey closed Whenvtl'ie latchbolt' is in thalioldingfposition Without;A retracti'ng` theE latch:boltbyr'manual op erationY ofl theactuatoir 39? Imthe disclosed: form;wherein tl'ieaxis'ilof tliepifn approaples alignment withtheaxesioit'liev pinsff 59? and? 38; the engagement of theangularlylfdisposedivedgek 6I- oftl're latch--boltrW-itl'rv tlie'- l'oor'jaInb'-y applies a component ofiforce tlircirglrfth-e linie 59i to movethe actuator' against" the biasing force# of the spring=y 43,permitting;` closure'off" the door and automatic latchingoperationawherrtlie=latch bolt isin-thefholding'fposition:

As illustrated' in- Fig: 4-,2 tlieVIV latnlrbolt" 56VIV is retainedinfthe-'retracted'position"when actuated thereto* by manual' I movement"ofi-"tile actuatorY 39' by virtuewof: the` alignment" of tl'ie axesofitlie pins 52, 59 and 60 Which'suppori the-'actuator and the link" 58It i`s understood-ofz course that t-lie1a-Xismofitliepixr'59Fmayh eitherbedrr alignment withr4 theu axes ofs the pins 52i andi" llliwhen thestops' (i2t and @are infcontactor'na'yj passisligltl'y beyond' that'Ypositi'oir of alignment? lfit-*were desired that tlieV l'atr'zhrmechanismslfionllz automatically return to the holding position aftermanual release; the axisf o theipinb 59Av wordt? approach butwoul'drea'ch"` alignment with-the pins 52n and* (IJv in-whiclrAinstance` the spring woulftlfreturnther latch-bolt* td the'lioldingposition- With the" disclosed l'at'ch meclr'xai'rismr irr whichthe actuator and latclrboltiareretainedlin the" retracted positionAafter manualLv opera-tion thereto; itf is reset forf holding 'the-idoor` closed by manuali' movementv of" the actuator onlinlt'to upsetthe"align-ment`- of'"the-axesoffthe pins 52"; 59 and 60 from the insideoff-*the*-door;

For7 purposes# off illustratingrthee construction and operation of themodified form Uf=` my1atich mechanism disclosedL inf-Bligsa 'Pto 123;Vinclusive,

Y the wall door-and keeperstructures-'mayfbe con'- sideredsimil'artothose previously-describedand arefreferred t@y by likereference-:numerals Although there are many features of similarityrbeetween thetwo.-disclosedflatclifmechanlsms, such the .ilushi 'mountingfof the latchf mechanism with; the e outer-*surface ofif'thelfdoor, theweather proof sealing ofthef accessfopenings: byftli'ex latch?actuating-'parts andi-'tlieuseoff'toggle connections forretaining thelaten boltlandfi actuator.z in the loldingforffretracted' positionsWherr'ma-nuall it Voperated. thereto@ the V modified-'1 formi' my:latcii mechanism shown in Figs. 'l to 13 inclusive has an actuator 19which permits full manual control of the latch mechanism from outsidethe door. In this instance, the door has two openings 12 and 19 whichare desirably near the side thereof opposite the hinge 24 andl arespaced for alignment with manually operable contact or button portions11i and 15 of the actuator 10.

For supporting the latch mechanism 16 in an operative position adjacentthe openings 12 and 13= in the door, it includes a base 11 which hasmounting flanges secured to the inner surface of the door by fasteningmeans such as the rivets as well as inwardly extending and substantiallyparallel supporting flanges 19. One face of the base 11 conforms to thesurface of the door against which it is mounted. In the midportion ofthe base and between the supporting flanges 19 is an opening 80 of asmaller size than the opening 12 in the door and which is substantiallyconcentric with respect to the opening 12 to provide a sealing surface82 for seating engagement with the button portion 14 of the actuator.

The latch actuator 19 has oppositely extending end portions or arms 83and 84 which carry the button portions 14 and 15 respectively inpositions for alignment with the openings 12 and 13 and is rotatablysupported intermediate its ends by a pin 85 which extends through thesupporting flanges 19 and a bearing portion 86 of the actuator. The pin85 is secured in place by fastening means such as a cross pin 81. Theextending end or arm S3 of the actuator is curved and extends outwardlythrough the opening 80 for movement of the button portion 14 toward andfrom the outer surface of the door, While the arm Sii carries the buttonportion 15 for movement toward and from the inner surface of the door.

The thickness of the button portion 14 is such that when it is seatedagainst the sealing surface 82, its surface is flush with the outersurface of the wall. The button portion 15 has a protruding mid-portionB8 adapted to t into the opening 13 and has an integrally flanged outeredge providing a sealing surface 89 which seats against the innersurface of the wall adjacent the opening 13. By this arrangement ofstructure, both openings 12 and 13 are closed and sealed by theirrespective button portions of the actuator and present surfaces flushwith the outer surface of the wall when the latch mechanism is in theholding position, as shown in Fig. 9. In addition, and since the buttonportions 14 and 15 are opposite sides of the actuator support pin 95,the effect of air pressure against the two button portions tends tobalance so as to avoid a tendency for the air pressure to effect anundesired release of the latch mechanism.

A latch bolt 99 is rotatably supported between the supporting flanges 19adjacent the end of the arm 83 of the actuator by a pin 92 which extendsthrough the supporting flanges and a bearing portion 93 of the latchbolt. The pin 92 is held in position by suitable means such as a crosspin all. As in the previously described form of my invention, the latchbolt includes an integraljatching portion 95 for engagement with thekeeper 55 to hold the door in the closed position, as shown in Fig. 9.

At a position displaced from the axis of the latch bolt support pin 92,the latch bolt is rotatably connected to one end of a link 96 by a pin96. The other end of the link 91 is rotatably connected to the arm 83 ofthe actuator by a pin 9B so that the link forms an actuating connectionbetween the actuator 19 and the latch bolt 90. In addition to the link9B, and to provide a biasing force for holding the latch bolt in theposition to which it is last manually operated, a bowed compressionspring 99 has one end anchored to the latch bolt support pin 92 and itsother end connected to the pin 98.

In one position of the actuator 19, such as the closed or holdingposition indicated in Fig. 9, the pin 98 by which the link is connectedto the actuator arm, is on one side of a toggle action line passingthrough the axes of the pins 92 and 85 upon which the latch bolt andactuator respectively are supported. In this position of the actuator, acomponent of the biasing force of the spring 99 biases the actuator in adirection which maintains the seated relation of the button portions 14,15 with their respective sealing surfaces. In the other position of theactuator which is shown in Fig. l0, the pin 98 and the end of the spring99 which is connected thereto have crossed the action line of the togglepassing through the axes of the pins 92 and 85 and a component of theforce of the spring 99 biases the actuator to the open or retractedposition. Thus, the arm 83 of the actuator and the compression spring 99provide a toggle connection for maintaining the latch mechanism in theposition to which it is last operated.

In the holding position of the latch mechanism shown in Fig. 9, the axesof the pins 91 and 93 at the ends of the link 96 are in substantialalignment with the axis of the pin 85 which supports the actuator. Thisalignment of the axes of the pins 91, 98 and 85 substantially locks thelatch bolt in the holding position firmly to maintain that positionagainst any possible effects of vibrations or jarring when the door isclosed and prevents the closing of the door without manipulation of theactuator when the latch bolt is in the holding position. Thus the arm 83of the actuator and the link 96 form parts of a second toggle connectionwhich has a controlling influence upon theoperation of the latchmechanism.

Quick release of the door for opening is effected from outside the doorby manual force applied to the button portion 15 of the actuator.Closing of the door and its retention in the closed position by thelatch mechanism is effected by pushing the door shut and then applyingforce to the button portion 14 of the actuator.

From the foregoing description of the structure and operation of both ofthe disclosed forms of my latch mechanism, it may be understood thateach includes a combination of toggle connections wherein the actuatorserves as a part of the operating mechanism in addition to providing anexposed element for the manual operation of the latch. In both forms ofthe latch mechanism, the exposed portion or portions of the actuator areflush with the outer surface of the door so as to preserve thestreamlined surface. In addition, the joints between the actuator anddoor are sealed by the engagement of unexposed surfaces so as to beweather-tight and operable in adverse weather conditions. In each latchmechanism the disposition of parts is such that the latch bolt is firmlyheld in the holding position so that jolts and vibration cannot providean undesired release of the latch. Both latches may be quickly operatedand each remains in the position: to which it: is last operated untilthat:

position isy manually changed'.

While I have illustrated a preferred embodiment of my invention, manymodications may be mad'ei Without departing from the spirit of theYinvention, and I do not wish to be limited to the precise details ofconstruction set forth, but desire to avail myself of all changes withinthe scope of the appended claims.

Having thus described my invention, what` I claim as new and desire tosecure by Letters Patent of the UnitedStates, is:

1. A latch mechanism comprising, in combination, a base includingmounting flange portions and supporting flanges, said'base having anopening therein between the supporting ilanges, ay latchy actuatorrotatably secured to the basebetween the supporting ilanges for limitedSwingingA movement about a fixed axis, said actuator having manuallyoperable actuating portions on oppositev sides of the said axis ofswinging movement therefor, one or" said actuating portions extendingthrough saidopening in the base,` alatch bolt rotatablyV secured tothe-base by a support pin for swinging movement between holding andyretractedpositions, a link rotatably connected to the actuator and to'the latch boltl at` positions such that the axes of the rotatableconnecions to the link are substantially aligned with the axisofrswinging movement of the actuator when the latch bolt-is in saidholding position, a compression spring having one end anchored to'saidsupport pin and its other end connected to the actuator at a positionsuch that the action line o1- the spring crosses a line between theanchored end of the springV and the axis of, swinging movement of theactuator whereby said:

actuator isbiased toward the limit of swingingV movement to which it waslast operated.

2. In a latch mechanism adapted for mounting ush with the-outer surfaceof a door of an airplane or the like having adjacent openings. for theaccommodation of partsA of a latch actuator, the combination comprisinga base having an opening therein smaller than one of the openings 5 inthe door and mounted on the inner surface ofk the door adjacent said oneof the openings and providing an inner sealing flange, a latch actuatorhavingfoppositely lextending end-portions r for op-l erating; the:mechanism to. holding andv retracted positions,l onef ofi said. end.portions extending through said, openingE in the base. and having meansthereon', fitting;` intosaid fone: of: the openings in the door. in;-flush relationship to the outer surface. ofthe door,y and engaging saidinner*r sealingange; inone position. of the latch actuator; the other`of, said end portions includimg ,a-.portion fitting into-r the' other ofsaid openings imthedoor inffiush relatonship to the outer` surfaceofthef door and having an edge sealingfiiange-engaging thelinnersurface-0f the door inv-said. onev position ofi the latch actuator,andmeans rotatably-connecting thef latch actuator to-said baseintermediate said extending end portionsffor-fswinging-`r movement ofsaid endportions towardand fromithe-openings, in thefdoor,

ARNOLD F. GANDER.

REFERENCES CITED'V Thesrfollowing referencesare ofrecord in the file ofthis patent:

OTHER REFERENCES Publication Quick- ,Release Fasteners onGermaneAircraft, published-by the Royal-Aircraft Establishment (19431).,(pages 1 and2 and Fig. 3).

